| Title: | Ligand binding-dependent functions of the lipocalin NLaz: an in vivo study in Drosophila |
| Author(s): | Ruiz M; Ganfornina MD; Correnti C; Strong RK; Sanchez D; |
| Address: | "2Instituto de Biologia y Genetica Molecular, c/Sanz y Fores 3, Universidad de Valladolid-CSIC, 47003 Valladolid, Spain. lazarill@ibgm.uva.es" |
| ISSN/ISBN: | 1530-6860 (Electronic) 0892-6638 (Linking) |
| Abstract: | "Lipocalins are small extracellular proteins mostly described as lipid carriers. The Drosophila lipocalin NLaz (neural Lazarillo) modulates the IIS pathway and regulates longevity, stress resistance, and behavior. Here, we test whether a native hydrophobic pocket structure is required for NLaz to perform its functions. We use a point mutation altering the binding pocket (NLaz(L130R)) and control mutations outside NLaz binding pocket. Tryptophan fluorescence titration reveals that NLaz(L130R) loses its ability to bind ergosterol and the pheromone 7(z)-tricosene but retains retinoic acid binding. Using site-directed transgenesis in Drosophila, we test the functionality of the ligand binding-altered lipocalin at the organism level. NLaz-dependent life span reduction, oxidative stress and starvation sensitivity, aging markers accumulation, and deficient courtship are rescued by overexpression of NLaz(WT), but not of NLaz(L130R). Transcriptional responses to aging and oxidative stress show a large set of age-responsive genes dependent on the integrity of NLaz binding pocket. Inhibition of IIS activity and modulation of oxidative stress and infection-responsive genes are binding pocket-dependent processes. Control of energy metabolites on starvation appears to be, however, insensitive to the modification of the NLaz binding pocket" |
| Keywords: | "Aging/drug effects/genetics Alkenes/chemistry/metabolism Amino Acid Sequence Animals Animals, Genetically Modified Carrier Proteins/chemistry/*genetics/metabolism Cell Line Cell Survival/drug effects/genetics Drosophila Proteins/chemistry/*genetics/metabo;" |
| Notes: | "MedlineRuiz, Mario Ganfornina, Maria D Correnti, Colin Strong, Roland K Sanchez, Diego eng Research Support, Non-U.S. Gov't 2013/12/24 FASEB J. 2014 Apr; 28(4):1555-67. doi: 10.1096/fj.13-240556. Epub 2013 Dec 20" |
